Thread: arrays with different sizes..

i want to define arrays with different sizes..

something like this..

Code:

struct block{
	int id;
	int points[3];
	int cells[3];
	struct covar covariant[cells[0]][cells[1]][cells[2]];
};

however since cells is defined inside the same structure i cannot define it like this..
what is the way out??

can you elaborate..
afaik malloc is used for pointers..
i couldnt find its use to initialize arrays...

hey thanks that worked.. but i am unable to rewind the pointer.. how do i do that?

hi.. i ve been rtying to do what u said..
but it gives me segmentation fault as soon as i try to declare another pointer..
am i missing something here..

yes i got what you were trying to say..
but i just found that declaring any more pointers in my program causes seg. fault...
here's the code...
if i delelte any one of the colored part the seg. fault goes away ..
otherwise however.. any pointer declaration gives an error..
i have a 768 mb ram on my comp.. could it be a memory problem??

Code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "structures.c"

int main()
{
FILE *stream;

if((stream=fopen("block2.dat","r"))!=NULL){
	printf("Succesfully opened file\n");
}
else{
	printf("Failed to open file\n");
	exit(1);
}

char number[5];char temp[10];

char num_i[5],num_j[5],num_k[5];
int j=0;int k=0;int i=0;int l,m,z,loop_var;

fscanf(stream,"%s", number);
num_blocks=atoi(number);
printf("%i\n",num_blocks);
struct block arr_blocks[num_blocks];
int no_i,no_j,no_k,total_points;

for(i=0;i<num_blocks;i++){
	fscanf(stream,"%s	%s	%s", num_i,num_j,num_k);
	arr_blocks[i].id=i;
	arr_blocks[i].points[0]=atoi(num_i);
	arr_blocks[i].points[1]=atoi(num_j);
	arr_blocks[i].points[2]=atof(num_k);
	arr_blocks[i].cells[0]=(atoi(num_i))-1;
	arr_blocks[i].cells[2]=(atoi(num_j))-1;
	arr_blocks[i].cells[1]=(atoi(num_k))-1;
}

struct point *p_map,*p_map_2;
struct covar ***p_covariant[num_blocks];
struct contra ***p_contravariant[num_blocks];

for(loop_var=0;loop_var<num_blocks;loop_var++){
	total_points=(arr_blocks[loop_var].points[0])*
				(arr_blocks[loop_var].points[1])*(arr_blocks[loop_var].points[2]);

	//allocating memory for covar
	p_covariant[loop_var]= 
		(struct covar***)malloc(sizeof(struct covar**)*((arr_blocks[i].cells[0])));
	for (i=0; i<(arr_blocks[i].cells[0]); i++)
	{
		p_covariant[loop_var][i] = 
		(struct covar**)malloc(sizeof(struct covar*)*(arr_blocks[loop_var].cells[1]));
		for (j=0; j<(arr_blocks[loop_var].cells[1]); j++)
		{
			p_covariant[loop_var][i][j] =
				 (struct covar*)malloc(sizeof(struct covar)*
					(arr_blocks[loop_var].cells[2]));
		}
	}

	**p_covariant[loop_var]=&p_covariant[loop_var][0][0][0];

	p_contravariant[loop_var] = (struct contr..........*)malloc(sizeof(struct contr..........)*
					(arr_blocks[i].cells[0]));
	for (i=0; i<(arr_blocks[i].cells[0]); i++)
	{
		p_contravariant[loop_var][i] = 
		(struct contr..........)malloc(sizeof(struct contra*)*(arr_blocks[loop_var].cells[1]));
		for (j=0; j<(arr_blocks[loop_var].cells[1]); j++)
		{
			p_contravariant[loop_var][i][j] =
			 (struct contra*)malloc(sizeof(struct contra)
						*(arr_blocks[loop_var].cells[2]));
		}
	}
	**p_contravariant[loop_var]=&p_contravariant[loop_var][0][0][0];

	//Read all the co-ordinates from the file
	p_map=(struct point*)malloc(sizeof(struct point)*total_points);
	printf("%u\n",p_map);
	p_map_2=p_map;
	printf("%u\n",p_map_2);
	j=0;k=0;
	for(k=0;k<3;k++){
		for(i=0;i<total_points; i++){
			fscanf(stream,"%s",temp);
			(*p_map).coords[k]=atof(temp);
			p_map++;
		}
	}
}
return 0;
}